Investigation of Age Related Differences in the Rewiring of P2-Olfactory Receptor Neurons

Olfactory receptor neurons (ORNs) maintain the ability to regenerate. These neurons reside in the olfactory epithelium and project axons that connect to the olfactory bulbs. Despite the diffuse distribution of ORNs in the olfactory epithelium, they converge at discrete glomeruli in the olfactory bulb. In the P2 IRES tau-lacZ mouse, the P2 ORN subtype has been previously mapped to two glomeruli, using X-gal staining. To determine if age affects ORN regeneration, left olfactory nerve transections were performed on P2 mice from immature (five-weeks old) and mature (1 6-weeks old) groups. Following recovery, the olfactory bulbs were processed to observe ORN regeneration. A significant difference was seen in the number and mapping of full P2 glomeruli between lesioned and control olfactory bulbs, but not between the age groups. This suggests that age differences between the two groups in this study were not large enough to affect the regeneration of P2 ORNs